620 Ingenieurwissenschaften und zugeordnete Tätigkeiten
Refine
Departments, institutes and facilities
- Fachbereich Ingenieurwissenschaften und Kommunikation (180)
- Institut für Technik, Ressourcenschonung und Energieeffizienz (TREE) (118)
- Fachbereich Informatik (26)
- Fachbereich Angewandte Naturwissenschaften (24)
- Institute of Visual Computing (IVC) (9)
- Institut für Sicherheitsforschung (ISF) (8)
- Graduierteninstitut (6)
- Institut für Detektionstechnologien (IDT) (3)
- Zentrum für Innovation und Entwicklung in der Lehre (ZIEL) (3)
- Fachbereich Wirtschaftswissenschaften (1)
Document Type
- Conference Object (173)
- Article (119)
- Report (14)
- Part of a Book (11)
- Book (monograph, edited volume) (10)
- Doctoral Thesis (8)
- Patent (7)
- Bachelor Thesis (6)
- Master's Thesis (6)
- Diploma Thesis (5)
Year of publication
Keywords
- modeling of complex systems (6)
- advanced applications (5)
- gas transport networks (4)
- FPGA (3)
- Hydrogen storage (3)
- applications (3)
- efficiency (3)
- globally convergent solvers (3)
- mathematical chemistry (3)
- observational data and simulations (3)
In this paper, the performance evaluation of Frequency Modulated Chaotic On-Off Keying (FM-COOK) in AWGN, Rayleigh and Rician fading channels is given. The simulation results show that an improvement in BER can be gained by incorporating the FM modulation with COOK for SNR values less than 10dB in AWGN case and less than 6dB for Rayleigh and Rician fading channels.
The need for innovation around the control functions of inverters is great. PV inverters were initially expected to be passive followers of the grid and to disconnect as soon as abnormal conditions happened. Since future power systems will be dominated by generation and storage resources interfaced through inverters these converters must move from following to forming and sustaining the grid. As “digital natives” PV inverters can also play an important role in the digitalisation of distribution networks. In this short review we identified a large potential to make the PV inverter the smart local hub in a distributed energy system. At the micro level, costs and coordination can be improved with bidirectional inverters between the AC grid and PV production, stationary storage, car chargers and DC loads. At the macro level the distributed nature of PV generation means that the same devices will support both to the local distribution network and to the global stability of the grid. Much success has been obtained in the former. The later remains a challenge, in particular in terms of scaling. Yet there is some urgency in researching and demonstrating such solutions. And while digitalisation offers promise in all control aspects it also raises significant cybersecurity concerns.
The transport of carbon dioxide through pipelines is one of the important components of Carbon dioxide Capture and Storage (CCS) systems that are currently being developed. If high flow rates are desired a transportation in the liquid or supercritical phase is to be preferred. For technical reasons, the transport must stay in that phase, without transitioning to the gaseous state. In this paper, a numerical simulation of the stationary process of carbon dioxide transport with impurities and phase transitions is considered. We use the Homogeneous Equilibrium Model (HEM) and the GERG-2008 thermodynamic equation of state to describe the transport parameters. The algorithms used allow to solve scenarios of carbon dioxide transport in the liquid or supercritical phase, with the detection of approaching the phase transition region. Convergence of the solution algorithms is analyzed in connection with fast and abrupt changes of the equation of state and the enthalpy function in the region of phase transitions.
AErOmAt Abschlussbericht
(2020)
Das Projekt AErOmAt hatte zum Ziel, neue Methoden zu entwickeln, um einen erheblichen Teil aerodynamischer Simulationen bei rechenaufwändigen Optimierungsdomänen einzusparen. Die Hochschule Bonn-Rhein-Sieg (H-BRS) hat auf diesem Weg einen gesellschaftlich relevanten und gleichzeitig wirtschaftlich verwertbaren Beitrag zur Energieeffizienzforschung geleistet. Das Projekt führte außerdem zu einer schnelleren Integration der neuberufenen Antragsteller in die vorhandenen Forschungsstrukturen.
In this paper, modeling of piston and generic type gas compressors for a globally convergent algorithm for solving stationary gas transport problems is carried out. A theoretical analysis of the simulation stability, its practical implementation and verification of convergence on a realistic gas network have been carried out. The relevance of the paper for the topics of the conference is defined by a significance of gas transport networks as an advanced application of simulation and modeling, including the development of novel mathematical and numerical algorithms and methods.
The formulation of transport network problems is represented as a translation between two domain specific languages: from a network description language, used by network simulation community, to a problem description language, understood by generic non-linear solvers. A universal algorithm for this translation is developed, an estimation of its computational complexity given, and an efficient application of the algorithm demonstrated on a number of realistic examples. Typically, for a large gas transport network with about 10K elements the translation and solution of non-linear system together require less than 1 sec on the common hardware. The translation procedure incorporates several preprocessing filters, in particular, topological cleaning filters, which accelerate the solution procedure by factor 8.
The paper presents the topological reduction method applied to gas transport networks, using contraction of series, parallel and tree-like subgraphs. The contraction operations are implemented for pipe elements, described by quadratic friction law. This allows significant reduction of the graphs and acceleration of solution procedure for stationary network problems. The algorithm has been tested on several realistic network examples. The possible extensions of the method to different friction laws and other elements are discussed.
The general method of topological reduction for the network problems is presented on example of gas transport networks. The method is based on a contraction of series, parallel and tree-like subgraphs for the element equations of quadratic, power law and general monotone dependencies. The method allows to reduce significantly the complexity of the graph and to accelerate the solution procedure for stationary network problems. The method has been tested on a large set of realistic network scenarios. Possible extensions of the method have been described, including triangulated element equations, continuation of the equations at infinity, providing uniqueness of solution, a choice of Newtonian stabilizer for nearly degenerated systems. The method is applicable for various sectors in the field of energetics, including gas networks, water networks, electric networks, as well as for coupling of different sectors.
Die Norm EN ISO 13849-1 stellt explizite Anforderungen an sicherheitsgerichtete SPS-Software. Wie lassen sich diese im Maschinenbau praxisgerecht umsetzen? Mit dieser Frage hat sich ein von der DGUV gefördertes und an der Hochschule Bonn-Rhein-Sieg durchgeführtes Projekt beschäftigt. Der Beitrag skizziert die Vorgehensweise zur möglichen Umsetzung der normativen Anforderungen. Diese Vorgehensweise ist unabhängig von der verwendeten Sicherheits-SPS und daher allgemein anwendbar. Es wird auf insgesamt 10 dokumentierte Beispiele und einen ausführlichen Forschungsbericht verwiesen, die downloadbar sind.
Automatisierungstechnik
(2006)
Für die Entwicklung steuerungstechnischer Sicherheitsfunktionen muss ab 2012 die Normen EN ISO 13849-1 oder EN 62061 befolgt werden, die sowohl Anforderungen an die Hardware als auch Anforderungen an die Software beschreibt. Die Anforderungen an die Software spielten bis vor einigen Jahren kaum eine Rolle, da Sicherheitsfunktionen vorzugsweise in Hardware realisiert wurden. Heutzutage ist es jedoch sehr häufig üblich, Sicherheitsfunktionen mit einer dafür geeigneten programmierbaren SPS zu realisieren. Die neuen Normen bzgl. der sicheren Steuerung von Maschinen verlangen neben der Quantifizierung der Hardware-Ausfallraten von Sicherheitsfunktionen noch ein Management der Sicherheitsfunktionen. Dazu gehört auch ein Management der Softwareentwicklung für Sicherheitsfunktionen, um systematische Fehler zu minimieren. Dieses Management der Softwareentwicklung wird im Wesentlichen durch das V-Modell repräsentiert. Für die Maschinebauindustrie darf dieser Managementprozess nicht zu aufwendig sein, ansonsten wird dieser in der Praxis nur schwer angenommen. Eine Möglichkeit der Abarbeitung des V-Modells wird vorgestellt. Wahrscheinlich ist diese aufgezeigte Möglichkeit für die Industrie noch zu aufwendig.
Automatisierungstechnik
(2014)
Die Automatisierungstechnik wird aus praktischer Sicht mit vielen Beispielen und zahlreichen Bildern veranschaulicht. Studenten ingenieurwissenschaftlicher Fachrichtungen sowie Ingenieure und Techniker in der Ausbildung und der beruflichen Praxis können sich auf dem Stand der Technik selbständig einarbeiten.
DeltaV Neural ist eine Softwareapplikation innerhalb des Prozessautomatisierungssystems DeltaV, die es dem Anwender ermöglicht, auf einfache Art und Weise Softsensoren zu konfigurieren. Softsensoren besitzen die Aufgabe, schwer messbare oder nur in großen Zeitabständen ermittelbare Prozessausgangsgrößen mittels einfacher und schneller messbarer Ersatzmessgrößen zu schätzen bzw. vorherzusagen.
Dem RTPM (Real-Time Performance Monitoring) wurde in den letzten Jahren in der Automatisierungstechnik immer mehr Beachtung geschenkt. Drei ausgewählte Aspekte des RPTM werden behandelt: Alarmanalyse, Reglerperformance und Stelleinrichtungen. Die Reduktion von Alarmmeldungen mit Hilfe einer Alarmanalyse wird mit Hilfe von Beispielen aus der Industrie veranschaulicht. Ziel einer Analyse ist die Identifikation von (1) falschen Alarmgrenzen, (2) Reglern, bei denen Störungen im Handbetrieb ausgeregelt werden, (3) Reglern, bei denen Betriebspunktänderungen im Handbetrieb ausgeführt werden, (4) Reglern mit Stellgrößen bei 0% oder 100%, (5) falschen Reglerparametern sowie (6) Fehlern in der Messtechnik, Antrieben, Klappen oder Ventilen. Die industrielle Anwendung der Überwachung der Reglerperformance wird anhand des in das Prozessautomatisierungssystem DeltaV von Emerson Process Management integrierten Softwareproduktes DeltaV Inspect erläutert. DeltaV überwacht und bewertet (1) die Bereichsüberschreitungen der Regelgrößen und der Stellsignale, (2) die Betriebsarten (Hand oder Automatik) und (3) die Regelungsgüte. Die Regelungsgüte wird bei einem konstanten Sollwert und stochastischen Störungen aus dem Unterschied zwischen der tatsächlichen und der theoretisch erreichbaren Varianz des Regelfehlers berechnet. Anstelle einer Korrelations- bzw. Regressionsanalyse wird die theoretisch erreichbare minimale Varianz aus der aktuellen Varianz des Regelfehlers und der Varianz der Abweichung der aufeinander folgenden Regelfehlerabtastwerte berechnet.
In this contribution, we perform computer simulations to expedite the development of hydrogen storages based on metal hydride. These simulations enable in-depth analysis of the processes within the systems which otherwise could not be achieved. That is, because the determination of crucial process properties require measurement instruments in the setup which are currently not available. Therefore, we investigate the reliability of reaction values that are determined by a design of experiments.
Specifically, we first explain our model setup in detail. We define the mathematical terms to obtain insights into the thermal processes and reaction kinetics. We then compare the simulated results to measurements of a 5-gram sample consisting of iron-titanium-manganese (FeTiMn) to obtain the values with the highest agreement with the experimental data. In addition, we improve the model by replacing the commonly used Van’t-Hoff equation by a mathematical expression of the pressure-composition-isotherms (PCI) to calculate the equilibrium pressure.
Finally, the parameters’ accuracy is checked in yet another with an existing metal hydride system. The simulated results demonstrate high concordance with experimental data, which advocate the usage of approximated kinetic reaction properties by a design of experiments for further design studies. Furthermore, we are able to determine process parameters like the entropy and enthalpy.
Abschlussbericht zum BMBF-Fördervorhaben Enabling Infrastructure for HPC-Applications (EI-HPC)
(2020)
Hybrid system models exploit the modelling abstraction that fast state transitions take place instantaneously so that they encompass discrete events and the continuous time behaviour for the while of a system mode. If a system is in a certain mode, e.g. two rigid bodies stick together, then residuals of analytical redundancy relations (ARRs) within certain small bounds indicate that the system is healthy. An unobserved mode change, however, invalidates the current model for the dynamic behaviour. As a result, ARR residuals may exceed current thresholds indicating faults in system components that have not happened. The paper shows that ARR residuals derived from a bond graph cannot only serve as fault indicators but may also be used for bond graph model-based system mode identification. ARR residuals are numerically computed in an off-line simulation by coupling a bond graph of the faulty system to a non-faulty system bond graph through residual sinks. In real-time simulation, the faulty system model is to be replaced by measurements from the real system. As parameter values are uncertain, it is important to determine adaptive ARR thresholds that, given uncertain parameters, allow to decide whether the dynamic behaviour in a current system mode is the one of the healthy system so that false alarms or overlooking of true faults can be avoided. The paper shows how incremental bond graphs can be used to determine adaptive mode-dependent ARR thresholds for switched linear time-invariant systems with uncertain parameters in order to support robust fault detection. Bond graph-based hybrid system mode identification as well as the determination of adaptive fault thresholds is illustrated by application to a power electronic system easy to survey. Some simulation results have been analytically validated.
This book presents bond graph model-based fault detection with a focus on hybrid system models. The book addresses model design, simulation, control and model-based fault diagnosis of multidisciplinary engineering systems. The text beings with a brief survey of the state-of-the-art, then focuses on hybrid systems. The author then uses different bond graph approaches throughout the text and provides case studies.
Failure prognostic builds up on constant data acquisition and processing and fault diagnosis and is an essential part of predictive maintenance of smart manufacturing systems enabling condition based maintenance, optimised use of plant equipment, improved uptime and yield and to prevent safety problems. Given known control inputs into a plant and real sensor outputs or simulated measurements, the model-based part of the proposed hybrid method provides numerical values of unknown parameter degradation functions at sampling time points by the evaluation of equations that have been derived offline from a bicausal diagnostic bond graph. These numerical values are computed concurrently to the constant monitoring of a system and are stored in a buffer of fixed length. The data-driven part of the method provides a sequence of remaining useful life estimates by repeated projection of the parameter degradation into the future based on the use of values in a sliding time window. Existing software can be used to determine the best fitting function and can account for its random parameters. The continuous parameter estimation and their projection into the future can be performed in parallel for multiple isolated simultaneous parametric faults on a multicore, multiprocessor computer.
The proposed hybrid bond graph model-based, data-driven method is verified by an offline simulation case study of a typical power electronic circuit. It can be used to implement embedded systems that enable cooperating machines in smart manufacturing to perform prognostic themselves.
Analytical redundancy relations are fundamental in model-based fault detection and isolation. Their numerical evaluation yields a residual that may serve as a fault indicator. Considering switching linear time-invariant system models that use ideal switches, it is shown that analytical redundancy relations can be systematically deduced from a diagnostic bond graph with fixed causalities that hold for all modes of operation. Moreover, as to a faultless system, the presented bond graph–based approach enables to deduce a unique implicit state equation with coefficients that are functions of the discrete switch states. Devices or phenomena with fast state transitions, for example, electronic diodes and transistors, clutches, or hard mechanical stops are often represented by ideal switches which give rise to variable causalities. However, in the presented approach, fixed causalities are assigned only once to a diagnostic bond graph. That is, causal strokes at switch ports in the diagnostic bond graph reflect only the switch-state configuration in a specific system mode. The actual discrete switch states are implicitly taken into account by the discrete values of the switch moduli. The presented approach starts from a diagnostic bond graph with fixed causalities and from a partitioning of the bond graph junction structure and systematically deduces a set of equations that determines the wanted residuals. Elimination steps result in analytical redundancy relations in which the states of the storage elements and the outputs of the ideal switches are unknowns. For the later two unknowns, the approach produces an implicit differential algebraic equations system. For illustration of the general matrix-based approach, an electromechanical system and two small electronic circuits are considered. Their equations are directly derived from a diagnostic bond graph by following causal paths and are reformulated so that they conform with the matrix equations obtained by the formal approach based on a partitioning of the bond graph junction structure. For one of the three mode-switching examples, a fault scenario has been simulated.
Bond graph software can simulate bond graph models without the user needing to manually derive equations. This offers the power to model larger and more complex systems than in the past. Multibond graphs (those with vector bonds) offer a compact model which further eases handling multibody systems. Although multibond graphs can be simulated successfully, the use of vector bonds can present difficulties. In addition, most qualitative, bond graph–based exploitation relies on the use of scalar bonds. This article discusses the main methods for simulating bond graphs of multibody systems, using a graphical software platform. The transformation between models with vector and scalar bonds is presented. The methods are then compared with respect to both time and accuracy, through simulation of two benchmark models. This article is a tutorial on the existing methods for simulating three-dimensional rigid and holonomic multibody systems using bond graphs and discusses the difficulties encountered. It then proposes and adapts methods for simulating this type of system directly from its bond graph within a software package. The value of this study is in giving practical guidance to modellers, so that they can implement the adapted method in software.
Das Fraunhofer Institut für Intelligente Analyse- und Informationssysteme (IAIS) entwickelt im Projekt ProfiBot ein modulares Roboterbaukastensystem für die berufliche Mechatronikausbildung. Es wird durch das Bundesministerium für Bildung und Forschung (BMBF) gefördert. Diese Arbeit hat die Entwicklung eines Systems zum Ziel, mit dem es möglich ist, einen ProfiBot-Roboter an einer Dockingstation zu positionieren und eine Ladung der Akkus durchzuführen. Dies umfasst die Entwicklung der Algorithmen und Architekturen zur Navigation, die Konstruktion und die Herstellung der Dockingstation. Das System wurde so konzipiert, dass es sich gegenüber verschiedenen Störfaktoren, wie beispielsweise unterschiedlichen Lichtverhältnissen, Bodenbeschaffenheiten oder markanten Objekten im Raum, robust verhält.
3D Time-of-Flight (ToF)
(2012)
3D-Imaging
(2009)